Coolant distributor device



Dec. 13, 1966' (5, J AGULE ETAL 3,29L2Q2 COOLANT DISTRIBUTOR DEVICE Filed Aug. 12, 1963 2 Sheets-Sheet 1 FIGI H62 32 36 FW$ VOLUME FLOW PER UNIT AREA F (PRIOR ART) 3s 3 DISTANCE FROM BASE D: r g

3 C5 32% w c 46 5 DISTANCE FROM BASE INVENTORS GEORGE J AGULE ALFRED LEPLATTENIER G- J. AGULE ETAL COOLANT DISTRIBUTOR DEVICE Dec. 13, 1966 2 Sheets-Sheet 2 Filed Aug. 12, 1963 INVENTORS GEORGE J. AGULE ALFRED L'EPLATTENIER A GEN United States Patent Ofiice 3,291,202 COOLANT DISTRIBUTOR DEVICE George J. Agule, Stamford, Conn., and Alfred LEplattenier, Katonah, N.Y., assignors to The Machlett Laboratories, Incorporated, Springdale, Conn., a corporation of Connecticut Filed Aug. 12, 1963, Ser. No. 301,462 3 Claims. (Cl. 165-80) This invention pertains to distributor devices for cooling mediums, and more particularly to air distributors for use in connection with electron discharge devices of the air-cooled or finned-anode type.

As the design requirements of various electronic circuits progress in the art, there is an increasing demand for electron tubes of extremely large power capabilities. Generally, as the power rating of a tube is increased there is a corresponding increase in the amount of heat that the tube must dissipate. In some instances in the prior art, the heat produced by the high-power operation of an electron tube is removed by means of suitable liquid coolants, such as water, which are circulated through a cooling jacket. In other cases, the tube is fitted with a plurality of cooling fins or vanes between which a coolant, usually a gaseous medium such as air, passes to remove the heat therefrom. In order to render this latter form of cooling means as efiicient as possible, it has been customary to enclose the finned structure, which is usually attached to the tube anode, in a housing or conduit for directing forced air between the fins. Such housings are usually referred to as air distributors, whether the coolant medium is actually air or some other fluid.

One prevalent form of air distributor in the prior art which has proved rather satisfactory takes the general form of an annulus which is positioned around the cooling fins and which accepts a flow of cooling air at its base and expels the same along the inner surface of the annulus through one or more apertures in such inner surface. The height of the annulus (that is, the axial dimension) corresponds approximately to the vertical height of the finned array.

It has been observed that the finned radiating structures employed in this connection exhibit a heat pattern which indicates a need for more cooling at the upper portion of the radiators than at the lower. However, the air distributors and similar structures of the prior art have failed to provide an air flow of designed nonlinearity, especially where the actual volume of coolant flow per unit area during a given time is selectively increased by distributor design, so as to pass a greater volume rate of coolant where relatively greater cooling is needed.

It is accordingly a primary object of the present invention to provide a coolant distributor device for electron discharge devices or the like wherein the volume of coolant flow per unit area is rendered nonlinear in a designed manner over the length of the egress aperture in the distributor.

A more specific object of the present invention is to provide a coolant distributor device for electron discharge devices or the like wherein the volume of coolant flow per unit area through the egress apertures is selectively increased at a region along the length of the egress aperture in the distributor where relatively greater cooling is desired.

In accordance with the present invention, the above and other objects are achieved by means of a coolant distributor device comprising an elongate hollow member having an opening at the base thereof through which a flow of cooling air is admitted, along with a second 3,291,202 Patented Dec. 13, 1966 opening on a side wall of the elongate hollow member extending in the direction of the length thereof and acting as the egress aperture of the cooling medium. The hollow member has a cross sectional area which decreases as the distance from the base or ingress opening increases, and as a result the volume of the cooling fiuid expelled from the second or egress opening is greatest at the end thereof remote from the first opening. In a preferred form of the device of the present invention, a plurality of such elongate hollow members are arranged to form an annulus wherein the lengths of the several hollow members are substantially parallel to the central axis of the annulus. In this form, the cooling fluid is introduced into the bottom face of the annulus, and the egress apertures are along the inner, vertical face thereof. With the distributor positioned around a finned radiator assembly, the cooling medium flows inwardly of the annulus and between the several cooling fins. The taper of the several hollow members is such that the cross sectional area of each is less toward the top face of the annulus, and the hotter upper portions of the cooling fins are thus exposed to a greater volume of flow per unit area through the egress apertures than are the lower portions thereof.

With the above considerations and objects in mind, the invention itself will now be described in connection with a preferred embodiment thereof given by way of example and not of limitation, and with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a high power electron discharge device positioned within a coolant distributor of the general type to which the present invention pertains,

FIG. 2 is a schematic representation of the cross section of a coolant distributor of the prior art,

FIG. 3 is a graphical illustration of the volume of coolant flow per unit area through the egress apertures of the coolant distributor shown in FIG. 2,

FIG. 4 is a schematic representation of the cross section of a coolant distributor in accordance with the present invention,

FIG. 5 is a graphical illustration of the volume of coolant fiow per unit area through the egress apertures of the coolant distributor of the present invention shown in FIG. 4,

FIG. 6 is a vertical section view of a preferred form of the coolant distributor of the present invention, and

FIG. 7 is a plan view of the section shown in FIG. 6.

In FIG. 1, a typical high-power electron discharge device is indicated generally at 10, positioned within a coolant distributor 12 of the type to which the present invention generally pertains. A pair of cathode connector terminals 14 and 16 provide means for attaching respective connectors 18 and 20 for supplying the cathode current, and a grid connector terminal 22 lies just below the cathode terminals, with grid connector 24 attached thereto. The main body of the electron tube is positioned within the coolant distributor 12, and in the usual arrangement the tube is provided with an external anode having a plurality of cooling fins 25 attached thereto and lying within the path of coolant flow determined by the distributor 12, and this will be more clearly understood from the description that follows. A suitable base support 26 is also provided.

FIG. 2 is a schematic representation of the vertical section of an air distributor of the prior art, including a cylindrical housing 28 having an outer wall 30 and an inner wall 32 so as to constiute a hollow elongate annulus extending from an open base 34 to a closed top 36. The central portion of the annular distributor is open at both the top and bottom, so as to permit the insertion of an electron tube, as is indicated in FIG. 1.

As will be understood by those skilled in the art, the outer wall 30 is imperforate, while the inner wall 32 will normally include a plurality of elongate apertures 38 therein which permit the egress of the air or other coolant medium from the hollow annulus.

As may be seen in FIG. 2, both the outer wall 30 and the inner wall 32 are substantially cylindrical, with the spacing therebetween being constant from the base 34 up to the point where the outer wall 30 intersects the top 36. As the forced air or other coolant is introduced into the annular base opening 34, it flows upwardly within the hollow annulus between walls 32 and 30 and is then expelled inwardly of the annulus through the several apertures 38 in the inner wall 32. With an electron tube in place within the central opening of the distributor 28, the flow of air issuing from the several apertures 38 is directed over and between the anode cooling fins which are adjacent such apertures.

With this air distributor structure of the prior art as indicated in FIG. 2 it has been observed that the volume of coolant flow per unit area during a given time through the egress apertures which extend along the length o the elongate hollow annulus varies in a manner indicated generally by the curve of FIG. 3, wherein the ordinate indicates the volume flow per unit area, while the distance from the base 34 in FIG. 2 is plotted along the abcissa. As may be seen in FIG. 3, the volume rate of coolant flow through the egress apertures increases with distance from the input opening in the base 34 of the prior art distributor 28 in FIG. 2 up to a point which is slightly beyond the mid-point between the base and the closed top 36. For the remainder of the flow within the prior art distributor, the volume rate is found to decrease.

Since the heat pattern observed in the finned radiator anode cooling assemblies of most high-power electron tubes shows a higher temperature at the top portions of the fins than at the lower regions thereof, it is evident that more cooling is needed toward the tops of the anode fins. The shortcomings of the air distributors of the prior art are thus made rather apparent, since the volume rate of coolant flow therein decreases at the topthereof, just where an increase in the rate of volume flow is needed. As a result, the use of the air distributors of the prior art has sometimes been quite unsatisfactory, since in many instances there is an insufficient cooling of the anode fins, with resultant overheating and inalfunction in the operation of a high-power electron tube therein.

According to the present invention, the design of the coolant distributor is such as to provide an increase in the volume rate of flow of the coolant through the egress apertures at the top of the distributor device, where the additional cooling is needed in order to compensate for the relatively high temperature of the upper portions of the anode fins which are to be cooled by the distributor. FIG. 4 illustrates schematically the vertical section configuration of the coolant distributor 40 of the present invention. The inner wall 42 is substantially cylindrical, as in the case of the distributors of the prior art, and a plurality of egress apertures 44 is provided to permit the coolant to flow over the cooling fins of an electron tube which may be inserted within the annular distributor 40.

In sharp contrast to the configuration of the air distributors of the prior art, the distributor device 40 of the present invention includes an outer wall 46 which is frusto-conical in shape, with the diameter of the conical structure decreasing with increasing distance from the open base 48. The hollow elongate coolant flow passage defined by the inner wall 42 and the outer wall 46 is thus tapered from a maximum width at the base 48 to a minimum at the closed top 50.

In a manner analogous to the operation of the air distributors of the prior art, a flow of forced air or other coolant is introduced into the annular input opening in the base 48, and the coolant flows upwardly in the distributor between the inner wall 42 and the conical outer wall 46. Since the top 50 of the distributor is closed, the air is expelled inwardly of the annular distributor through the several apertures 44 in the inner wall 42 thereof. However, the analogy between the operation of the distributor of the present invention and that of the prior art devices ceases upon consideration of the volume rate of flow of the coolant therethrough, since the volume of coolant flow per unit area during a [give time through the egress apertures in the distributor of the present invention actually increases in the upper portion of the distributor, rather than decreasing as in the case of the prior art distributors.

While a mere casual consideration of the nature of the structure of the present invention might lead one to the conclusion that the taper in the outer wall provides only an increase in velocity of coolant flow, there is in actuality an increase in the volume flow per unit area, and it is to this end that the present invention is directed. That is to say, the design of the present invention is such as to increase the number of cubic feet per minute, rather than merely increasing the number of linear feet per minute, in the measure of coolant flow.

FIG. 5 illustrates the relationship between the volume rate of flow of coolant in the distributor 40 of the present invention with the distance along the elongate distributor from the open base 48. In comparing FIG. 5 with FIG. 3, it should be assumed that the same volume rate of flow is introduced into both the devices of FIGS. 2 and 4. As may be seen in FIG. 5, the volume rate of flow through the egress apertures 44 progressively increases along the entire length of the distributor, being greatest at the top thereof, rather than increasing over a portion of the distance and then decreasing as in the case of the distributors of the prior art. Thus, the present invention provides a greater volume of coolant flow per unit area out of the upper or smaller portion thereof, thus affording maximum cooling for the corresponding upper portions of the cooling fins of an electron tube which may be positioned within the center of the annular distributor 40.

FIG. 6 indicates in vertical section the details of one perferred form of an air distributor constructed in accordance with the principles of the present invention. The air distributor of FIG. 6 is indicated generally at 52, being shown mounted on a cylindrical support member 54 which serves not only as a means for mounting the air distributor, but also as the housing through which the flow of forced air or other coolant is directed to the base of the distributor 52. The distributor 52 is mounted on the .air conduit or housing 54 by means of suitable screws or the like (not shown) which connect the base 56 of the distributor 52 to the top of the housing 54.

The details of the construction of the distributor 52 will be better understood by considering the showings of FIGS. 6 and 7 together. A plurality of elongate tapered coolant flow passages 58, 60, 62 and 64 are shown, having respective inclined outer walls 66, 68, 70 and 72. A plurality of respective pairs of vertical walls, such as 74 and 76, form the sides of the several elongate coolant passages, with the inner of fourth wall of each of the passages being left open for the egress of the coolant flowing therethrough. This last-mentioned or open side of the coolant passage 60, for example, is defined by the base 56 and the top 78 of the distributor 52, along with the inner edges of the walls 74 and 76. The space between each adjacent pair of these elongate coolant flow passages, such as exists between side wall 74 and the adjacent side wall 80, provides a means of final egress for the coolant after it has passed over the finned structure with which the air distributor is designed to cooperate, as will be further described.

Each of the several elongate coolant passages in the distributor 52 includes an Opening in the base 56 thereof, with the ingress opening for passage 58 being indicated at 82. As may be seen in FIG. 7, the ingress aperture 82, as well as the several similar apertures 84, 86 and '88, is substantially triangular in shape, with such triangle being roughly defined by a base near the outer edge of the distributor base 56 and an apex near the inner edge of the base 56; the several respective apices shown in FIG. 7 are indicated by reference numerals 90, 92, 94 and 96.

The taper in the cross sectional area of the several coolant flow passages is a result of the incline of the several outer walls 66, 68, 70 and 72, and as may be seen in FIG. 6, these outer walls of the coolant passages extend from the respective ingress apertures in the base 56 of distributor 52 up to a closed smaller end at the top member 78 thereof. Outer wall 66 has a fiange 98 thereon which serves as an electrical connection to the distributor body.

While the distributor of the present invention is applicable to the cooling of any of several different varieties of finned anode structures or the like, one exemplary form of anode fin has been ch'osenfor the purposes of illustrating the cooperation with the distributor of the present invention, such exemplary anode being shown in part in phantom lines in FIGS. 6 and 7 herein. The several fins 100 are horizontally disposed within the distributor 52 when the electron discharge device (the envelope of which is indicated in phantom lines at 102) to be cooled is inserted within the distributor in the manner illustrated in FIG. 1 herein. The fins 100 are attached to the envelope 102 (usually comprising a portion of the anode assembly of the tube) in a series of circumferentially-spaced, vertically-stacked arrays. That is to say, each of the fins 100 shown in FIG. 7 lies above a vertical stack of spaced fins of similar configuration, each of which is attached to the tube envelope 102, with respective vertical spacer bars 104, 106 and 108 being employed at the outer extremities of the several vertical stacks of aligned fins. It will be noted in FIG. 7 that the open space between the fins associated with spacer bars 106 and 108 is in direct communication with the open inner face of the coolant flow passage 60, while the open space between vertical spacer bars 104 and 106 is in communication with the open space between side walls 74 and 80 of the coolant passages 60 and 58, respectively.

In the operation of the air distributor device of FIGS. 6 and 7, a flow of forced air or other coolant medium is introduced into the conduit or housing 54, whereupon the coolant flow is divided into a plurality of respective paths corresponding to the several elongate coolant passages, such as 58, 60, 62 and 64, since the central aperture in the base member 56 of the distributor 52 is tightly closed by the base of the electron tube placed in the distributor; the top aperture is similarly closed by the electron tube. As a result, the air enters apertures such as ingress aperture 82 and then flows upwardly through the tapered coolant passages and radially inward of the distributor 52 through the respective egress openings in the several coolant passages.

As is indicated by the arrows in FIG. 7, the air flowing radially inward from each of the coolant passages is divided into two oppositelydirected paths over the two adjacent sets of cooling fins, such respective paths being substantially arcuate in configuration, resulting in the final egress of the air (now heated by virtue of the heat exchange relationship with the several fins 100) through the open spaces between the several coolant flow passages. The cooling medium is thus introduced to the distributor at the base thereof in a direction substantially parallel with the axis of the distributor and the electron discharge device positioned therein, but the final discharge of the heated coolant medium is radially outward from the distributor. Where desired, a suitable outer housing can be employed to envelop the distributor 52, so as to carry away the heated coolant medium. As explained in connection with the earlier figures of the drawings herein, the gradual taper in the cross sectional area of the several coolant flow passages results in a greater volume of flow of the coolant through the egress apertures near the top 78 of the distributor 52 than at the lower portions thereof. In this manner, the fins nearer the top of the electron tube placed within the distributor 52, such fins being the hotter fins, are subjected to a greater flow of cool-ant medium, and a correspondingly greater heat transfer takes place at such upper fins.

The invention has been described above in some detail, and particularly with reference to its application to a hollow annular air distributor for use with high-power electron devices. However, it will be apparent to those skilled in the art that the invention is .also applicable to other forms of air distributors and the like. For example, if the device which is to be cooled is of such configuration as to not lend itself to insertion within an annular air distributor as shown herein, it will be understood that the concept of the present invention (wherein there is a designed increase in volume rate of How of coolant at a point where increased cooling is needed) is also applicable to coolant distributors in the form of a partial annulus, or even where the distributor wall containing the egress apertures is planar. The distributor of the present invention might therefore be in the form of an elongate tube or the like, with the coolant being introduced into an open end and being expelled through one or more apertures in the side wall. Further, even in the case of an annular distributor configuration, the annulus may be made up of a plurality of such individual elongate air distributor tubes or the like, similar to the prior art distributor shown in FIG. 1. Additionally, it will be appreciated by those skilled in the art that the concept of the present invention is not limited to the use of air as the coolant medium, since any other suitable fluid may also be employed. Hence, the invention is not to be con sidered as limited to the particular details given, nor to the specific application to which reference has been made during description of the device, except insofar as may be required by the scope of the appended claims.

What is claimed is:

1. A coolant distributor device for electron discharge devices and the like having an element which becomes heated and which requires a greater volume of coolant flow over a selected area than over other areas thereof, said distributor device comprising an elongate hollow member adapted to enclose the element to be heated and having a first opening at one end for the ingress of a cooling medium introduced under pressure, and having an elongate second opening on a side wall thereof directed toward said element and extending substantially the length thereof for the egress of such cooling medium, said hollow member having an inclined side wall directly opposite said second opening thereby providing the member with a cross sectional area which decreases with increasing distance from said first opening, the portion thereof having smallest cross sectional area being adapted to be positioned adjacent said element opposite said area thereof requiring greater volume of coolant flow, the volume of the cooling meduim expelled from said second opening being greatest at the end thereof remote from said first opening.

2. A coolant distributor device for electron discharge devices and the like having an element which becomes heated and which requires a greater volume of coolant flow over a selected area than over other areas thereof, said distributor device comprising an elongate hollow member adapted to enclose the element to be heated, one end of said member being closed and the other end including a first opening for the ingress of a cooling medium introduced under pressure, and an elongate second opening on a side wall of said elongate member directed toward said element and extending substantially the length thereof for the egress of such cooling medium, said hollow member having an inclined side wall directly opposite said second opening thereby providing the member with a cross sectional area which decreases with increasing distance from said first opening, the portion thereof having smallest cross sectional area being adapted to be positioned adjacent said element opposite said area thereof requiring greater volume of coolant flow, the volume of the cooling medium expelled from said second opening being greatest at the end thereof remote from said first opening.

3. A coolant distributor device for electron discharge devices and the like having an element which becomes heated and which requires a greater volume of coolant flow over a selected area than over other areas thereof, said distributor device comprising a plurality of elongate hollow members arranged to form an annulus for enclosing said element wherein the lengths of the several hollow members are substantially parallel to the central axis of such annulus, each of said elongate hollow members having a first opening at one end for the ingress of a cooling medium under pressure and an elongate second opening on the side wall facing inwardly of such annulus and directed toward said element and extending substantially the length of such elongate hollow member for the egress of such cooling medium, each of said hollow members having an inclined side wvall directly opposite said second opening thereby providing the member with a cross sectional area which decreases with increasing distance from said first opening, the portion thereof having smallest cross sectional area being adapted to be positioned adjacent said element opposite said area thereof requiring greater volume of coolant fiow, said first openings of the several said hollow members all lying in a common face of such annulus, the volume of the cooling medium expelled from said second openings being greatest at the ends thereof remote from said first openings.

References Cited by the Examiner UNITED STATES PATENTS 163,050 5/1875 Crocker 12699 2,532,858 12/1950 Rinia 165139 2,535,669 12/1950 Clay 16580 X 2,755,851 7/1956 Dow et al. 158114 JAMES W. WESTHAVER, Primary Examiner.

FREDERICK L. MATTESON, JR., Assistant Examiner. 

1. A COOLANT DISTRIBUTOR DEVICE FOR ELECTRON DISCHARGE DEVICES AND THE LIKE HAVING AN ELEMENT WHICH BECOMES HEATED AND WHICH REQUIRES A GREATER VOLUME OF COOLANT FLOW OVER A SELECTED AREA THAN OVER OTHER AREAS THEREOF, SAID DISTRIBUTOR DEVICE COMPRISING AN ELONGATE HOLLOW MEMBER ADAPTED TO ENCLOSE THE ELEMENT TO BE HEATED AND HAVING A FIRST OPENING AT ONE END FOR THE INGRESS OF A COOLING MEDIUM INTRODUCED UNDER PRESSURE, AND HAVING AN ELONGATE SECOND OPENING ON A SIDE WALL THEREOF DIRECTED TOWARD SAID ELEMENT AND EXTENDING SUBSTANTIALLY THE LENGTH THEREOF FOR THE EGRESS OF SUCH COOLING MEDIUM, SAID HOLLOW MEMBER HAVING AN INCLINED SIDE WALL DIRECTLY OPPOSITE 